JPS6235814A - Molding equipment - Google Patents

Abstract

PURPOSE:To reduce the distance between cavities, runners and gates and heaters so as to reduce the delay in heat transfer and consequently to solve the trouble of heating delay by a structure wherein the cavities, runners and gates are assembled in the interior of plates, in which heaters are arranged. CONSTITUTION:When resin flows out of a cull 7 into main runners 8 and runners 9, center blocks 1a and 2a are cooled by the resin, the temperature of which is relatively lower than those of the blocks. By detecting the tempera ture drops of the center blocks 1a and 2a, thermocouples 20 turn ON heaters 19 in order to heat the center blocks 1a and 2a. At this time, the main runners 8 and the runners 9 are rapidly and effectively heated, because both the heaters 19 and the center blocks 1a and 2a are assembled in the interior or retainer plates 3a and 4a. After that, when the resin is successively poured from the runners 9 of the center block through the gate 12 of each cavity 10, the tempera ture of chase blocks 1b and 2b are lowered at every cavity 10. At this time, the thermocouples 20 detects the temperature drops and turn ON the heaters 19.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to molding technology, particularly transfer molding technology, and relates to a technology that is effective when used to mold non-hermetically sealed packages, for example, in the manufacture of semiconductor devices. .

[Background technology]

In the manufacture of semiconductor devices, a chase block in which cavities, gates, runners, etc. are formed is held in a template, and a heater is built into this template as a transfer molding machine for molding non-hermetically sealed packages. Some molds are configured to control mold temperature using a thermocouple built into the mold plate.

However, in such transfer molding equipment,
Because the heater is located far from the cavity and runner, even if the heater starts heating with the thermocouple, it takes time for the heat to be transferred to the cavity and runner.
The problem is that there is a delay in temperature control.
revealed by the inventor.

In addition, examples of transfer molding technology include:
Published by Kogyo Kenkyukai Co., Ltd. "Electronic Materials November 1983 Special Edition" Published November 15, 1983 P151-P15
There is 7.

[Purpose of the invention]

An object of the present invention is to provide a molding technique that can ensure accurate temperature control.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, by incorporating the cavity, runner, and gate inside the template where the heater is placed, the distance between the cavity, runner, gate, and the heater can be shortened, and the short heat transfer distance reduces heat. This is designed to reduce the transmission delay and eliminate the heating delay.

〔Example〕

FIG. 1 is a longitudinal sectional view showing a transfer molding apparatus according to an embodiment of the present invention, and FIG. 2 is a partial plan view taken along line 1--2 in FIG.

In this embodiment, this molding apparatus is configured to mold a non-hermetically sealed pancage of a semiconductor device,
It includes an upper mold 1 and a lower mold 2.

The upper mold 1 and the lower mold 2 are respectively attached to upper mold mounting units 1 to 3 and lower mold mounting units 4, and are configured to be clamped together by a mold opening/closing cylinder device (not shown). The mounting unit 3.4 includes a template 3a,
4a, outer frames 3b, 4b, and spacer blocks 3c, 4
It is composed of c.

The upper mold 1 and the lower mold 2 are respectively composed of center blocks la and 2a in the center and a plurality of chase blocks 1b and 2b.
A is formed with a bot 6 into which a plunger 5 for pumping resin as a molding material is inserted, and a bot 6 is formed in the lower mold 2.
A cull 7 is formed at a position corresponding to the bot 6 of the center block 2b. The center block 2b of the lower mold 2 has a main runner 8 communicating with the cull 7 and a main runner 8.
A runner 9 is formed that communicates with a cavity to be described later. A plurality of cavities 1° are formed in the mating surfaces of the chase blocks 1b and 2b, and each cavity 10 is communicated with the runner 9 via a sub-runner 11 and a gate 12, respectively.

The upper mold 1 and lower mold 2 constructed in this manner are respectively embedded in the joint surfaces of the mold plates 3a and 4a in the upper and lower mounting units 3.4.

Further, an ejector mechanism is attached to the upper/lower die mounting unit 3.4, and the ejector mechanism ejects the molded product from each cavity 10 after resin molding with an ejector pin 13.
It is configured to protrude at 14. The ejector pin 13.14 has its rear end head attached to the upper/lower mounting unit 3.4.
It is surrounded by an ejector pin plate 15.16 and a retainer plate 17.18 which are arranged within.

Ejector pins 13.14 are connected to templates 3a, 4a, center blocks 1a, 2a and chase blocks 1b, 2.
b, and its tip faces the bottom of the cavity 10, the main runner 8, and the sub-runners 9 and 11. The ejector pin 13 of the upper mold is positioned at the bottom of the cavity 10 when the mold is closed by a spring, but after the mold is opened, the restoring force of the spring pushes it into the cavity 10 from the bottom of the cavity, etc., and releases the molded product. It acts like pushing out. The ejector pin 14 of the lower mold is positioned at the bottom of the cavity etc. when the mold is closed by a spring, but after the mold is opened, it is pushed up by another mechanism of the retainer plate 18 and the upper end plunges into the cavity etc. to release the molded product. Perform extrusion.

A long rod-shaped heater 19 is installed inside the upper and lower template plates 3a and 4a.
A plurality of thermocouples are arranged in parallel in parallel, and a thermocouple 20 as a temperature regulator detects the temperature on the lower mold plate 4a and controls the heater 19, thereby controlling the temperature of the mold plates 3a and 4a. is configured to adjust.

Next, the action will be explained.

The lead frame of the semiconductor device is placed on the mating surface of the lower die 2,
When the pellet and bonding wire that are the objects to be sealed are positioned so as to be accommodated in the cavity 10, the upper mold 1 and the lower mold 2 are brought together by the mold opening/closing cylinder device to form the cavity 10. .

When the upper and lower molds 1 and 2 are brought together with a predetermined mold clamping force, the tablet, which has been pre-formed with resin as a molding material and placed into the bot 6, is lowered by a transfer cylinder device (not shown) into the plunger 5. by runner 8.9
is pushed out. The tablet is heated and melted by a heater 19, and the resin is transferred in a molten state through runners 8, 9, and 11, and is injected and filled into each of the cavities 10 through the gate 12. When the resin filled in the cavity 10 is further heated, it hardens to form a pancage.

By the way, the temperature of the resin at the initial stage of transfer is the mold temperature (for example, 1
80℃) compared to 80℃ to 90℃,
The mold will be cooled by the transferred resin. Therefore, it is considered that it is desired to control the heater so as to return the temperature of the mold to a predetermined value.

Here, if the heater and the cavity are far apart, even if the thermocouple is placed near the cavity, from the time when the thermocouple works and the heater starts heating, until the heat is transferred to the cavity. This results in a delay in the cavity reaching the control temperature, resulting in poor temperature control.

In this example, a center block and a chase block are embedded in a template with a built-in heater, and a thermocouple is inserted into the template, so delays in heat transfer are avoided and temperature control is achieved properly. is realized.

That is, when the resin from the cull 7 flows into the main runner 8 and the runner 9, the center blocks 1a and 2a are cooled by the relatively low temperature resin 41.

When the temperature of the center block 18% 2a decreases, the thermocouple 20 detects this and turns on the heater 19, so the heater 19 heats the center blocks 1a and 2a. At this time, both the heater 19 as a heating means and the center blocks la and 2a as objects to be heated are connected to the templates 3a and 4a.
Since the main runner 8 and the runner 9 are installed inside the main runner, the distance between the heating means and the heated object is short, and the heating of the main runner 8 and the runner 9 is carried out quickly and effectively so that their temperature does not drop.

Subsequently, the resin flows from the runner 9 of the center block to the sub-runner 11 of the chase block 2b, and is sequentially injected from the gate 12 into each cavity 10 arranged along the sub-runner 11.
b, 2b is cooled for each cavity 10.

At this time, the chase blocks lb, 2b are assembled into the templates 3a, 4a containing the thermocouple 20 and the heater 19, and the distance between the chase blocks lb, 2b and the heater 19 is short, so the thermocouple detects the temperature drop. When the heater 20 is turned on, the heat from the heater 20 heats each cavity without delay, so that each cavity 10 is heated quickly and effectively. In this way, each cavity 1
0 is controlled to a predetermined temperature without delay.

Thereafter, the upper and lower molds 1.2 are opened by the mold opening/closing cylinder device, and the semiconductor device with the pellet etc. sealed in the molded pancage is removed from the cavity 10 by the ejector pins 13.14.

〔effect〕

(By incorporating cavities, runners, and gates inside the template where the reheater is installed, the heat transfer distance can be shortened and heating delays due to heat transfer delays can be prevented, allowing accurate Temperature control can be ensured.

(2) By preventing a delay in heating, the molten state of the resin can be maintained constant during the transfer of the runner and throughout the injection into each cavity, so the molding time can be shortened.

(3) By preventing a delay in heating, the temperature of the cavity, which has temporarily decreased during transfer, can be restored more quickly, thereby preventing insufficient curing of the resin.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the cavities, gates, runners, and bots are not limited to being formed in the chase block or center block and embedded in the template, but may be formed directly in the template.

[Application field]

In the above explanation, the invention made by the present inventor was mainly applied to a molding apparatus for molding a puff cage in a semiconductor device, which is the field of application to which the invention was made, but it is not limited thereto, and other applications may be used. It can also be applied to molding equipment etc. that mold products.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a transfer molding apparatus according to an embodiment of the present invention, and FIG. 2 is a partial plan view taken along line nn in FIG. 1. 1... Upper die, 2... Lower die, 1a, 2a... Center block, 1b, 2b... Chase block, 3.4
... Mounting unit, 5... Plunger, 6... Bot, 7... Cal, 8... Main runner, 9...
Runner, 10...Cavity, 11...Subrunner, 12...Gate, 13.14...Ejector pin, 15.16...Ejector pin plate, 17.1
8... Retainer plate, 19... Heater, 20.
・Thermocouple (temperature adjuster).

Claims (1)

[Claims] 1. A cavity inside the template on which the heater is placed;
A molding device characterized by incorporating a runner, a gate, and a pot. 2. The molding apparatus according to claim 1, wherein a chase block in which a cavity and a gate are formed, and a center block in which a runner is formed are respectively embedded inside the template. 3. The molding apparatus according to claim 1, wherein the cavity, gate, and runner are formed directly on the mold plate.